Trying to wire a MTH signal to FasTrack. Can someone tell me if this wiring is correct? It has three wires. Red. Black. Green.
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Maybe, maybe not.
What is the catalog number and description? Do you have the diagram for connecting to RealTrax or tubular?
This one is more complicated, having an upper and lower light.
https://mthtrains.com/sites/de...ction/30as11788i.pdf
This one I also need to figure out
Both of your signals require a 2-output occupancy detector. That is, turn on the Red circuit when occupied, else turn on the Green circuit when empty. This is done using a 2-output relay where one output is called "NO" and the other "NC". You'll see those same NO and NC references in the MTH instructions whether it be for the ITAD (or Lionel 153IR) occupancy detector or the pressure-plate detector (or Lionel 153C).
If using the insulated-rail method for occupancy detection, then a relay is the closest exit. For example here's one from Azatrax. (Note: see revised diagram in later post)
With its screw-terminal connections, no soldering is required.
Most guys are after plug-and-play and $10 per relay (plus shipping) is reasonable enough - case closed.
But if willing to mess around with a bit more wiring, there have been several OGR threads showing alternatives for less than $5 per signal.
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this is exactly what i was looking for. came through on search several times but i wasn't sure if it was right.
i am very interested in the "more wiring". can you point me in that direction? Finally have a permanent layout and several accessories to wire.
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Here's one way for about $3.50 (free shipping from Asia). Photo hijacked and annotated for clarity from this OGR thread which explains it in greater detail. The linked thread has additional discussion worth exploring. I think its self-explanatory as to how this "drops in" to replace the Azatrax relay in the previous diagram...or just ask for clarification.
I take it you have 2 or 3 signals. If you are talking, say, half a dozen or more signals, then somewhere I've posted and can dig up a plan B that drives the cost down to maybe $2 per signal relay.
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It always amazes me when an electronics manufacturer puts in a diagram that is technically wrong, Per Azatrax's website:
"Here we use one of the relay contacts to control a two-color train signal. When a train is in the block the relay will be energized and the '2C' contact connects with the '2NO' contact. This completes the circuit for the red light, and the signal will show red, indicating the block is occupied."
Yet, the diagram clearly shows the insulated block is "occupied" by the metal wheel sets so that contact 2C should be connected to 2NO, not connected to 2NC. No wonder we non-electrical types have trouble figuring things out. I know they go on to explain how the green light is displayed later, but the picture should still correctly reflect what they are trying to explain.
Stan, in your "annotated" photo, does the black wire go to "Accessory Common" and can both "Accessory Hot" white wires go to the same power post?
Thanks,
Chuck
Good catch Chuck! Here's a revised diagram showing the two scenarios.
PRR1950 posted:...Stan, in your "annotated" photo, does the black wire go to "Accessory Common" and can both "Accessory Hot" white wires go to the same power post?
Yes. Black wire to "Accessory Common" which in this case is also the outer rail.
Yes. Both "Accessory Hot" are the same voltage in this example. Since most layouts have an "Accessory Hot" distribution bus running around the track, this would tap into that whether it be with a terminal strip, bus bar, wire nuts, whatever. Well, to be precise, when using the Azatrax relay or the eBay relay method you could have separate/different Accessory Hot power supplies. For example you might have a 12V DC-output wall-wart that you want to use to power DC-capable accessories. That is, in a typical train transformer with AC Accessory power output, any Watts consumed for accessories means that much less available Watts for track/motive power. For established layouts, it's probably a hassle to retrofit/re-wire a DC accessory bus. But if planning a new layout, I recommend at least thinking through this option. In round numbers, low-voltage DC costs about 5-10 cents per Watt whilst low-voltage AC costs about 50c - $1 per Watt.
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